In a Physiology lecture, the professor asked us, "Who agrees that positive feedback is not a homeostatic mechanism?" He then asked the ones who did raise their hands to stand up. He applauded them, "These people are thinkers. Positive feedback isn't a homeostatic mechanism."

I didn't raise my hand, so I guess I was wrong. But after reading through some clinical physio books and searching the net, everyone seems to agree that positive feedback is part of homeostasis. I haven't been able to catch my professor to question him further.

Well, I would say, it's not, because by itself it does not lead to homeostasis. However, other mechanisms follow, which lead to homeostasis. It would be probably best to ask your professor next time. This way you will prove that you have really thought about it and didn't just randomly raise your hand

What you say makes sense. I'll be sure to ask him whether positive feedback is related to homeostasis in any way, or not. As well as present him with the books that claim positive feedback to be a part of homeostasis. He once mentioned he'd sue any book that claims so

A number of synthetic and response mechanisms use positive feedback to amplify the system - that's part of overall homeostasis. If you focus on JUST that process, and ignore that the feedback can be stopped, it looks like it's not homeostatic. It seems like the professor is playing semantic games and ignoring the system.

The question to ask is, if there are natural positive feedback systems (other than those associated with diseases), how could they NOT be homeostatic?